can't get ecu to reset

[ak_mattv]

I have a 92 eclipse 1.8L auto. The check engine light was on so i pulled the codes and got 13(IAT), 15(Idle speed control motor position sensor), 21(ECT), and 25(Barometric pressure sensor). Now i replaced everything except number 15 cause i don't know what or where that is, if anyone knows info would be helpful..., and rechecked the ecu, same 4 codes are popping up. So i thought ya know maybe i have to reset the ecu, i tried leaving the battery disconnected overnight, unplugging the ecu for 20-25 minutes but the same codes are still being thrown right away like it never reset at all?!? I'm not sure but when you turn your key to ON the cel should be lit for 5 sec and go off right? Mine just stays on. I live in Fairbanks,AK and right now it gets about 0 out at night and the will not start, just cranks and cranks, but if i put it in the shop for like 5 min it fires right up. So i was just wondering if i am missing something for the ecu reset or not? And if there are any other DSM owners out here in Fairbanks that might wanna take a look at her.... heated shop.... free coffee...

 

[skatershawn]

Number 15 or the ISC is on you throttle body... it controls the air flow into your intake mani at idle!
the motor will move in and out to help get the correct air flow!
i Actually have one i got from the dealership (cause thats the only place i could find that carried them) and turned out that wasn't my problem so i just swapped a 6 bolt into it!
If you need it pm me and we can set something up!

[dealership charged me $380 for it, call around and see what you find]

good luck!

 

[Colt4G63 also]

Test the circuits for all the items that are throwing codes first, but I'm thinking your ECU might be shot. I have an ECU from a 93 Eclipse 2.0 n/t laying around that had the exact same symptom. I swapped out the ECU and the codes were all gone. I still haven't figured out how to repair that particular ECU.

 

[steve]

The 1.8L ECUs also suffer from caps leaking just like the 2.0L ones do. That sounds like what your problem may well be and not all the stuff changed.

Pull it and take a look or post an infocus picture of the board and I'll tell you what I see.
I have a couple of repaired MD159561 sitting on the shelf downstairs.

 

[ak_mattv]

OK i pulled the ecu apart and it all looked good, no leaking caps, nothing, looked new. The main problem i am having is the car will not start when its cold. It just cranks and cranks but doesn't catch. After about 5 min of cranking it will start then die. After a couple more trys it starts and idles real low around 500 rpms. When it warms up it idle's fine around 800 rpms, drives fine. Could the ecu be the problem even though it looks perfect?

 

[steve]

If it wasn't for the CEL codes and the idle problems which point at the ECU then next suggestion would be to check the engine coolant sensor.

I'm not as familiar with the ways in which the 1.8L fails as with the 2.0L engines.